Stress reactions to cognitively demanding tasks and open-plan office noise.
OBJECTIVE
To investigate the effects of cognitively demanding work tasks and office noise on heart rate variability (HRV), cardiovascular responses and electromyography (EMG) activity in the trapezius muscles.


METHODS
Ten female volunteers were exposed to simulated open-plan office noise for 35 min (Leq 65 dBA), while engaged in cognitively demanding tasks. Task performance, self-rated stress and energy, affective state, perceived exertion in the shoulders and in the head, EMG in the left and right trapezius muscle, blood pressure, heart period length, HRV, and salivary cortisol were measured.


RESULTS
Cognitively demanding work tasks were associated with changes in HRV, systolic blood pressure and EMG that reflects increased sympathetic activity in the autonomic nervous system. No effect of noise was observed, except for a higher rating of perceived exertion in the head and, contrary to expectations, a 4% lower diastolic blood pressure in the noise conditions.


CONCLUSIONS
Psychophysiological measures reflected the mental load imposed by cognitive work tasks. Short-term exposure to office noise resulted in increased ratings of perceived exertion in the head, but not in physiological stress reactions.
Kristiansen
Jesper
J
National Research Centre for the Working Environment, Lersø Parkalle 105, 2100, Copenhagen, Denmark. jkr@nrcwe.dk
Mathiesen
Line
L
Nielsen
Pernille Kofoed
PK
Hansen
Ase Marie
AM
Shibuya
Hitomi
H
Petersen
Helga Munch
HM
Lund
Søren Peter
SP
Skotte
Jørgen
J
Jørgensen
Marie Birk
MB
Søgaard
Karen
K
D000328:Adult; D000342:Affective Symptoms / Q000503:physiopathology / Q000523:psychology; D001794:Blood Pressure / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006321:Heart / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000503:physiopathology; D009623:Noise, Occupational / Q000009:adverse effects*; D005082:Physical Exertion / Q000502:physiology; D012463:Saliva / Q000737:chemistry; D013315:Stress, Psychological / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D013647:Task Performance and Analysis
D006854:Hydrocortisone